Basic steps involved in the fabrication of integrated optical elements will be presented. Emphasis will be put on the development steps required to establish an Integrated Optical Technology based on silicon, which includes from the definition of the waveguide structure to the fabrication and characterization procedures. Aspects such as the numerical simulation of the components, the design of the optical element suitable as sensor, the analysis of the light input coupling methods, and the process parameters fitting according to the required materials will be highlighted in this paper. Finally, two examples will be presented, show its applicability of the developed technological steps. An "optode," or optical absorption sensor, suitable for the measurement of chemical concentration of a given ion in solution, due to modulation of the complex part of the refractive index (RI), and a biosensor based on the coupling efficiency of an optical waveguide cantilever.